Hemophagocytic lymphohistiocytosis in a patient with Legionella infection and bone marrow monotypic plasma cells in the setting of chronic lymphocytic leukemia

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition in which the body makes too many activated immune cells (macrophages and lymphocytes) that phagocytose hematologic cells. HLH can be inherited or acquired. Acquired HLH has been associated with: infection, immunosuppressive medications, autoimmune diseases, certain cancers, and metabolic diseases. Here, we report the case of a 50 year old male with a history of chronic lymphocytic leukemia Rai Stage IV status post chemotherapy and a recent admission for Legionella pneumonia who presented with worsening fever despite levofloxacin treatment and marked hypercalcemia. A bone marrow biopsy showed 20–30% lambda‐restricted plasma cells. Additionally, hemophagocytosis was found in the bone marrow, which prompted the clinician to consider HLH in the diagnosis. After further testing, the patient met the criteria for HLH with an H‐score of 234 (98.4% probability of patient having HLH). Despite steroid treatment, the patient's condition deteriorated and the patient died 6 days after bone marrow biopsy.